We are particularly interested in the phylogenetic relationships between extinct and extant species but we also work on purely extant groups, including primates, honeycreepers and sharks. One group we have a long-term interest in are proboscideans, with a number of recently extinct members that are amenable to ancient DNA analyses, which we have used to determine the phylogenetic position of the woolly mammoth and the African forest elephant. We are also working on sea cows, including the extinct Stellers sea cow, the scimitar cat Homotherium and the extinct giant beaver Castoroides.